The next challenge is to weld in the new floor, which has made me decide that I really need to rotate the chassis safely and accurately. After doing some research I decided to purchase two engine mount stands which I will bolt on to the front and rear sections of the chassis. I found two on ebay that seemed to be ok and they turned up today! I have to say that for £36 each I am really impressed with the quality. They seem high enough to allow a full rotation, but I will need to create some bespoke fitting plates with some adjustment in them just to make sure they do rotate.
Next steps will be to buy some more steel plate for the bespoke fittings so I will report back when that is done and then I will be able to weld in the floor, I can't wait for that!!